Ali named for Cassius Marcellus Clay 1810-1903 Republican. He was an abolitionist and was shot at an abolitionist meeting in 1843. He recovered and survived an assassination attempt by six men in 1849, killing one of them. Yet Ali said he "ain't having no slave name". This to explain his name change. I did read he joined the Muslims to keep organized crime figures away.
Cassius Clay changed his name to Muhammad Ali in 1966. After the Israeli victory in the 1967 Six Day War, he briefly changed his name again to Morris Steinberg.
;^)